The present invention relates to coatings comprising an organometallic compound, a fluorinated solvent, and co-solubilizing agent. In embodiments, the co-solubilizing agent is a fluorinated co-solubilizer. In embodiments, a fluorinated tail is added to an organometallic compound to cause the organometallic compound to become soluble in a fluorinated solvent. In embodiments, the organometallic compound, which is normally not soluble in fluorinated solvents, becomes completely miscible in fluorinated solvents. In embodiments, the co-solubilizer does not act as a catalyst, but instead, acts as a filler, and is present in the coating composition. Such coating compositions can be used in many arts such as, for example, electrical arts, electrostatographic arts, computer arts, and the like. In embodiments, the composition coating material can be useful as, for example, electrically or thermally conductive soluble fluoropolymer-ceramic hybrids or intermediates, electroluminescent fluorinated fluids or polymer coatings, photosensitive fluorinated fluids or coatings, colored fluorinated fluids or soluble polymer coatings for display devices, fluorinated carrier fluids for metal oxide film formation (where low surface tension of fluorinated fluids are desirable), thermochromic fluorescent or electrochromic fluorinated fluids or coatings, wire coatings such as electrode wire coatings, and many other applications.
Fluorinated solvents are preferred vehicles for many substances. Fluorinated solvents are preferred because they are thermally insulative, have low surface energy, can have low boiling points, and can be recyclable or recoverable,
A problem results in that many substances are not soluble in fluorinated solvents. For example, many organic molecules and many non-fluorinated or partially fluorinated compounds, are not soluble in fluorinated solvents. Specifically, most, if not all, organometallic compounds, and especially superconductors or superconductor precursors, are not soluble in fluorinated solvents.
Attempts have been made to render previously fluoro-insoluable materials soluble in fluorinated solvents. These attempts include using fluoro-ponytails (e.g., long carbon chains consisting mainly of perfluoroalkyl segments) as co-solvents. These ponytails greatly increase solubility in the fluorous phase. Many approaches are discussed below. However, in all these approaches, the co-solvent is used as a catalyst and can be separated at the end of the reaction.
A paper by the University of Leicester Department of Chemistry (http://www.le.ac.uk/chemistry/research/epsrc/egh1.html, Aug. 28, 2001) entitled, xe2x80x9cCatalysis in the Fluorous Biphase,xe2x80x9d discloses methods for preparation of catalysts derivatised with perfluoroalkyl substitutents to evaluate the criteria for preferential fluorous phase solubility and to investigate the influence of the perfluoroalkyl groups on the properties and activities of the metal catalyst.
A paper from Chemtech October 1999 (pp. 7-12) by Hans-Joachim Lehmler et al. entitled, xe2x80x9cLiquid Ventiliationxe2x80x94A New Way to Deliver Drugs to Diseased Lungs?,xe2x80x9d discloses ways of enhancing solubility in perfluorocarbon solvents of drugs.
A paper from Science, Vol. 275, Feb. 7, 1997 (pp. 823-826) by Armido Studer et al. entitled, xe2x80x9cFluorous Synthesis: A Fluorous-Phase Strategy for Improving Separation Efficiency in Organic Synthesisxe2x80x9d teaches a xe2x80x9cfluorous synthesisxe2x80x9d approach in which organic molecules are rendered soluble in fluorocarbon solvents by attachment of a suitable fluorocarbon group.
A paper from Science, Vol. 266, Oct. 7, 1994 (pp. 72-75) by Istvan T. Horvath et al. entitled, xe2x80x9cFacile Catalyst Separation without Water: Fluorous Biphase Hydroformulation of Olefinsxe2x80x9d discloses the application of fluorous biphase system for the extraction of rhodium from toluene and for the hydroformylation of olefins.
A paper from Science, Vol. 266, Oct. 7, 1994 (pp. 55-56) by J. A. Gladysz, entitled, xe2x80x9cAre Teflon xe2x80x9cPonytailsxe2x80x9d the Coming Fashion for Catalysts?xe2x80x9d discusses use of long carbon chains consisting mainly of perfluoroalkyl segments called xe2x80x9cponytailsxe2x80x9d appended to increase solubility in the fluorous phase and serve as de facto anchors.
A paper from Chem. Commun., 1998 (pp. 1531-1532) by David E. Bergbreiter et al. entitled, xe2x80x9cA Soluble Fluorous Phase Polymer Support,xe2x80x9d discloses preparation of a soluble fluorocarbon polymer that has reactive sites that can be used to covalently bind reagents and to render them soluble in the fluorous phase as a polymer-bound reagent.
A paper from Journal of Pharmaceutical Sciences, Vol. 87, No. 12, December 1998 (pp. 1585-1589) by Thomas D. Williams et al. entitled, xe2x80x9cSolubility Enhancement of Phenol and Phenol Derivatives in Perfluorooctyl Bromide,xe2x80x9d discusses examining the use of a hydrophobic solubilizing agent capable of interacting with model drug solutes by hydrogen bonding with the purpose of enhancing solubility in perfluorooctyl bromide.
A paper from Journal of Fluorine Chemistry 101, 2000, (pp. 247-255) by Pravat Bhattacharyya et al., entitled xe2x80x9cPhosphorus (III) Ligands in Fluorous Biphase Catalysis,xe2x80x9d discloses the synthesis, coordination chemistry and catalytic applications of a series of perfluoroalkyl-substituted phosphorus (III) ligands.
A paper from Journal of Fluorine Chemistry 99, 1999, (pp. 197-200) by Eric G. Hope et al., entitled xe2x80x9cThe Rhodium Catalyzed Hydrogenation of Styrene in the Fluorous Biphase,xe2x80x9d discloses the use of rhodium-catalyzed hydrogenation of styrene as a system to study the influence of the perfluorocarbon and organic solvents and the perfluoroalkyl-ponytails on an application of the fluorous biphase approach to homogeneous catalysis.
A paper from Journal of Fluorine Chemistry 100, 1999, (pp. 75-83) by Eric G. Hope et al., entitled xe2x80x9cFluorous Biphase Catalysis,xe2x80x9d discusses the evolution and future prospects for the fluorous biphase approach to homogeneous catalysis.
A paper from Journal of Fluorine Chemistry 107, 2001, (pp. 141-146) by Hans-Joachim Lehmler et al., entitled xe2x80x9cBehaviour of Partially Fluorinated Carboxylic Acids at the Air-Water Interface,xe2x80x9d discloses langmuir isotherms for several acids.
A paper from Chemtracts-Inorganic Chemistry Vol. 7 1995 (pp. 14-18) by I. T. Horvath et al., entitled, xe2x80x9cFacile Catalyst Separation Without Water: Fluorous Biphase Hydroformylation of Olefins,xe2x80x9d discloses the utility of a new simple scheme to effect catalyst/product separation in homogeneous catalysis.
However, it is sometimes desired that a fluoro-solubilizing co-solvent not be used as a catalyst as it is used in the above listed experiments. This is necessary when it is not suitable to include the step of separating the catalyst from the fluorinated solution. Such a situation may include creating a coating by mixing several compounds together.
Embodiments of the present invention include: an organometallic coating composition comprising an organometallic compound, a fluorinated solvent, and a co-solubilizer comprising a fully fluorinated polymer, wherein said organometallic compound is miscible in said organometallic coating composition.
Embodiments further include: an organometallic coating composition comprising an organometallic compound selected from the group consisting of a superconductor and superconductor precursor, a fluorinated solvent, and a co-solubilizer comprising a fully fluorinated polymer, wherein said organometallic compound is miscible in said organometallic coating composition.
In addition, embodiments include: an organometallic coating composition comprising an organometallic compound, a fluorinated solvent, and a copolymer of tetrafluoroethylene and an oxy-halo perfluoropolymer, wherein said organometallic compound is miscible in said organometallic coating composition.
The present invention relates to organometallic coating compositions for many applications. The coating composition comprises an organometallic compound, a co-solubilizer, and a fluorinated solvent. In embodiments, the co-solubilizing agent is a fully fluorinated co-solubilizer. In embodiments, a fluorinated tail is added to an organometallic compound to render soluble the organometallic compound in a fluorinated solvent. In embodiments, the organometallic compound, which is normally not soluble in fluorinated solvents, becomes completely miscible in fluorinated solvents due to the addition of the fully fluorinated co-solubilizer. In embodiments, the fluorinated co-solubilizer does not act as a catalyst, but instead, acts as a filler or additive, and is present in the final organometallic composition. In embodiments, a co-solubilizer comprises a fully fluorinated polymer.
The term xe2x80x9cfully fluorinated polymersxe2x80x9d as used herein, refers to fluorinated polymers that do not contain any hydrocarbon chains, hydrocarbon units, hydrocarbon substituents, or any carbon-hydrogen bonds. The term xe2x80x9cfully fluorinated polymersxe2x80x9d includes polymers comprising fluorinated monomers containing no hydrocarbon units, and monomers that are fully fluorinated and do not contain any hydrocarbon units. In embodiments, the fully fluorinated polymers are soluble in fluorinated solvents. In embodiments, the fully fluorinated polymers may be amorphous, thereby giving them excellent light transmission properties. In embodiments, the fully fluorinated polymers are solution coatable and have a low surface energy, and therefore, smooth, thin and uniform low surface energy coatings can result. In embodiments, the fully fluorinated polymer is a co-solubilizer, and promotes solubility in fluorinated solvents, materials which are not normally soluble in fluorinated solvents.
A co-solubilizer is a substance, which when added to a mixture renders the solute of that mixture soluble by reaction with the solute. A co-solubilizer is normally soluble in the solvent. Without the co-solubilizer, the solute would otherwise not be soluble in the solvent.
Examples of suitable fully fluorinated polymers include perfluorinated siloxanes, perfluorinated styrenes, perfluorinated urethanes, copolymers of fluoropolymers and perfluoropolymers such as, copolymers of tetrafluoroethylene and fully fluorinated polymers, and copolymers of tetrafluoroethylene and oxygen-containing fully fluorinated polymers, copolymers of tetrafluoroethylene and oxy-halo-fully fluorinated fluoropolymers, and mixtures thereof.
In embodiments, the fully fluorinated polymer comprises the following Formula I:
((CF2)mxe2x80x94(X)n)o
wherein m is a number of from about 1 to about 100, or from about 2 to about 50, or from about 5 to about 25; n is a number of from about 1 to about 100, or from about 2 to about 50, or from about 5 to about 25; and o is a number of from about 1 to about 100, or from about 2 to about 50, or from about 5 to about 25; and wherein X is selected from the group consisting of unsubstituted or substituted, straight or branched chain fluorocarbons having from about 1 to about 50 fluorocarbons, or from about 2 to about 25 fluorocarbons; and substituted or unsubstituted cyclic fluorocarbons having from about 3 to about 20 fluorocarbons, or from about 4 to about 10 fluorocarbons; and substituted or unsubstituted oxy-halo fluorocarbons having from about 3 to about 10 fluorocarbons, or from about 4 to about 6 fluorocarbons. Other possible substituents for X include hexafluoropropylene, and/or perfluoroalkoxy substituted tetrafluoroethylene.
In embodiments, the fully fluorinated polymer has the following Formula II:
(CF2)mxe2x80x94(X)n
wherein m, n and X are as defined in Formula I.
In embodiments, the fully fluorinated polymer has the following Formula III: 
wherein p is a number of from about 1 to about 100, or from about 2 to about 50, or from about 5 to about 25; and q is a number of from about 1 to about 100, or from about 2 to about 50, or from about 5 to about 25. A commercially available perfluoropolymer having the above Formula III is TEFLON(copyright) AF, a copolymer of tetrafluoroethylene and perfluoro-2,2-dimethyl-1,3-dioxide, the latter monomer being fully fluorinated.
In embodiments, the fully fluorinated polymer has the following Formula IV:
((CF2)mxe2x80x94Xxe2x80x94(CF2)r)o
wherein r is a number of from about 0 to about 50, or from about 1 to about 25, or from about 2 to about 15; and wherein X, m and o are as defined for Formula I.
In embodiments, the fully fluorinated polymer has the following Formula V: 
wherein o is as defined in Formula I; s is a number of from about 0 to about 5, or from about 1 to about 3, or 2; t is a number of from about 0 to about 25, or from about 1 to about 15, or from about 5 to about 10; and u is a number of from about 0 to about 5, or from about 1 to about 3, or 2. A commercially available example of a perfluoropolymer having the above Formula IV is CYTOP(copyright) available from Asahi Glass Company.
Another specific example of a fully fluorinated material is AUSIMONT(copyright) Fluorolink F7004 from Ausimont, Thorofare, N.J. This fully fluorinated polymer is useful in solubilizing in fluorinated solvents, materials that are not normally soluble in fluorinated solvents. This fully fluorinated polymer works well as a co-solubilizer for copper complexes such as copper (ii) hexafluoropentanedionate. The fully fluorinated polymer acts as a co-solubilizer which covalently bonds the superconductor or superconductor precursor.
The fully fluorinated coating material compound or composition is present in the coating composition in an amount of from about 0.1 to about 40 percent by weight of total solids, or from about 2 to about 15 percent by weight of total solids. Total solids as used herein, refers to the total amount by weight of fully fluorinated material, fillers, additives, organometallic materials such as superconductors or superconductor precursors, and other like ingredients contained in the coating solution.
An organometallic compound is present in the coating composition. The addition of the co-solubilizer renders the organometallic compound totally miscible in the fluorinated solvent.
A superconductor precursor or superconductor can be used in the coating composition as the organometallic compound. Examples of superconductors or superconductor precursors include, for example, metal alkoxides, multidentate ligands of conductive metals, other superconductors, other superconductor precursors, or mixtures thereof.
The term xe2x80x9csuperconductorsxe2x80x9d as used herein refers to metals, alloys and compounds which have the ability to lose both electrical resistance and magnetic permeability at or near absolute zero. In other words, superconductors have infinite electrical conductivity at or near absolute zero. Superconductivity does not normally occur in alkali metals, noble metals, ferro- and antiferromagnetic metals. Usually, elements having 3, 5, or 7 valence electrons per atom can be superconductors. Examples of superconductors include metals having 3, 5 or 7 valence electrons.
A superconductor precursor is a material that may be processed to form a superconductor. Organometallic compounds are typically processed via chemical vapor deposition (CVD) to produce films which can be either superconductors or can possess other unique properties such as chemochromic or thermochromic properties. MOCVD refers to metal-organic chemical vapor deposition. Organometallics that can be processed to create superconductor films are referred to as superconductor precursors.
Other examples of suitable superconductors include metal oxide superconductors comprising admixtures of metals from Groups IB, IIA, and IIIB of the Periodic Table. Illustrative materials of such type include the metal oxide superconductors of the yttrium-barium-copper type (YbBa2Cu3Oy) type, the so-called xe2x80x9c123xe2x80x9d high temperature superconductors (HTSC) materials, wherein y may be from about 6 to about 7.3, as well as materials where Y may be substituted by Nd, Sm, Eu, Gd, Dy, Ho, Yb, Lu, Y0.5xe2x80x94Sc0.5, Y0.5xe2x80x94La0.5, and Y0.5xe2x80x94Lu0.5, and where Ba may be substituted by Srxe2x80x94Ca, Baxe2x80x94Sr, and Baxe2x80x94Ca. Another illustrative class of superconductor materials includes those of the general formula (AO)mM2Canxe2x88x921CunO2n+2, wherein the A cation can be thallium, lead, bismuth, or a mixture of these elements, m=1 or 2 (but is only 2 when A is bismuth), n is a number of from about 1 to about 5, M is a cation such as barium or strontium, and the substitution of calcium by strontium frequently is observed, as described in xe2x80x9cHigh Tc Oxide Superconductors,xe2x80x9d MRS Bulletin, January, 1989, pp. 20-24, and xe2x80x9cHigh Tc Bismuth and Thallium Oxide Superconductors,xe2x80x9d Sleight, A. W., et al., MRS Bulletin, January, 1989, pp. 45-48. Other examples include Yba2Cu3O7xe2x88x92x (see P. P. Edwards et al. Chemistry Britain, 1987, pp. 23-26; Pb2Sr2LnCu3)O8-x (see M. O""Keefe et al., J. Am. Chem. Soc. 1988, 110, 1506; La2xe2x88x92xSrXCuO4 (see Bednorz and Muller, Z. Phys. B. Cond. Matter, 1986, 64, pp 189-195, and the like.
Specific examples of superconductors or precursors of superconductors include organometallic compounds such as copper (II) hexafluoropentanedionate, copper (II) methacryloxyethylacetonacetonate, antimony ethoxide, indium hexafluoropentandionate, and the like, and mixtures thereof. Some of these may not be necessarily considered superconductors, but may be considered direct precursors for superconductors via a chemical coating process such as chemical vapor deposition (CVD). Other organometallic fillers include monodentate, bidentate, or multidentate ligands such as beta-diketonates, cyclopentadienyls, alkyls, perfluoroalkyls, alkoxides, perfluoroalkoxides, and Schiff bases. Other examples of bidentate or multidentate ligands may comprise oxyhydrocarbyl ligands, nitrogenous oxyhydrocarbyl ligands, or fluorooxyhydrocarbyl ligands. The multidentate ligand may be selected from the group consisting of amines and polyamines, bipyridines, ligands of the Formula IV: 
wherein G is xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94; or xe2x80x94NRxe2x80x94, wherein R is H or hydrocarbyl; crown ethers or cryptates; and ligands of the formula R0O(C(R1)2C(R2)2O)nR0, wherein R0 is selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, cyanato, perfluoroethyl, perfluoro-n-propyl, or vinyl; R1 is hydrogen, fluorine, or a sterically acceptable hydrocarbyl substituent; R2 is hydrogen, fluorine or a sterically acceptable hydrocarbyl substituent; n is 4, 5, or 6, and R0, R1 and R2 may be the same or different from each other.
Examples of organometallic additives also include those having the following Formula VII: 
where M may be selected from the group consisting of Al, Ba, Be, Bi, Cd, Ca, Ce, Cr, Co, Cu, Ga, Hf, In, Ir, Fe, Pb, Li, Mg, Mn, Mo, Ni, Pd, Pt, K, Dy, Er, Eu, Gd, Ho, La, Nd, Pr, Sm, Sc, Tb, Tm, Yb, Y, Rh, Ru, Si, Ag, Na, Sr, Ta, Tl, Sn, Ti, V, Zn, Zr, and the like; X or Y may be a hydrocarbon chain having from about 1 to about 30 carbons, or from about 3 to about 12 carbons; a fluorocarbon having from about 1 to about 30 carbons or from about 3 to about 12 carbons, or having from about 1 to about 20 fluorocarbon units of from about 3 to about 8 fluorocarbon units; a substituted or unsubstituted alkoxy group such as methoxy, propoxy, ethoxy, butoxy, pentoxy, and the like; substituted or unsubstituted a cyclic group having from about 4 to about 12 carbons such as cyclobutane, cyclopentane, benzene, a phenyl group such as phenol, cycloheptane, and the like; and wherein n is a number of from about 1 to about 100, or from about 1 to about 20, or from about 1 to about 4.
The organometallic compound may be present in the coating composition in any desired amount. Examples of amounts include from about 10 to about 250 parts per hundred, or from about 25 to about 200 parts per hundred, or from about 50 to about 200 parts per hundred organometallic material:polymer.
Any suitable fluorinated solvent may be used with the fully fluorinated polymer and optional metal material. A fluorinated solvent is a solvent comprising fluorine. In embodiments, the fluorinated solvents have low surface energy and low surface tension. Examples of fluorinated solvents include any partially fluorinated organic molecule having a carbon chain with from about 2 to about 25 carbons, or from about 5 to about 15 carbons, and in embodiments, contains carboxylic acid functionality.
The process for solubilizing an organometallic compound in a fluorinated solvent to form an organometallic solution includes adding and reacting a co-solubilizer, an organometallic compound, and a fluorinated solvent. Unlike in known processes, the co-solubilizer does not act like a catalyst. Instead, the co-solubilizer acts as a filler or additive, and is present in the final organometallic solution. In known processes, fluorinated co-solubilizers act as catalysts and are not xe2x80x9cused upxe2x80x9d in the reaction, and do not become part of the final solution. Instead, in known processes, the fluorinated co-solubilizers can be easily and readily separated out of the final solution. In the present process, the fluorinated co-solubilizer is xe2x80x9cused upxe2x80x9d in the process, is present in the final solution, and is not readily or easily separated out of the final solution. The fluorinated solvent in the present process has the ability to cause the organometallic compound or superconductor to become miscible in the fluorinated solvent.
In known processes of fluorous biphase catalysis, the organometallic compound is solubilized in the fluorinated solvent via similar methods described here. The catalysis reaction occurs when an aqueous phase (containing reactants) is combined into one single phase at a temperature at which the aqueous phase and a given fluorinated solvent phase are miscible. When the reaction is completed, the temperature of the reaction vessel is then returned to a temperature where the aqueous and fluorinated phase are once again immiscible. The catalyst remains in the fluorinated phase where it can be re-used, while the product of the reaction is emulsified or soluble in the aqueous phase.
All the patents and applications referred to herein are hereby specifically, and totally incorporated herein by reference in their entirety in the instant specification.
The following Examples further define and describe embodiments of the present invention. Unless otherwise indicated, all parts and percentages are by weight.